2.0 Analysis 2.1 The Flight The crew were qualified for the flight, the weather was favourable for the flight, and there were no problems reported with the aircraft. The crew were also familiar with the airport. This very probably explains why they decided to make a straight-in approach rather than fly a circuit as recommended in the AIP. The accuracy of the distances and flight times transmitted by the crew indicates that they were using the GPS as an aid to navigation, particularly in view of the fact that the Blanc-Sablon DME was not in service at the time of the occurrence. Speed calculations indicate that, when the co-pilot transmitted their position as 16 miles and six minutes from the airport, the descent had probably commenced. Though their position and time of arrival were mentioned, their altitude was not. This indicates either that the crew felt very comfortable with their altitude or that they had not checked their altitude with the same degree of care as they had checked their GPS data. The altimeter setting was the same throughout the flight; it is plausible that the correct setting was displayed on the instrument, and that a correct reading of aircraft altitude was possible. It was not necessary to do a reset or to visually check the barometric scales to confirm the position or cause the crew to look at the altimeter. Another possibility is that the pilot who was monitoring the altitude misread the altimeter. 2.2 Visual Contact The normal route of the aircraft passed to the east of le au Bois, at the location and time that the witnesses saw the flashing light. At that location, the altitude of the aircraft was unusually low. The analysis of the pieces recovered from the aircraft does not indicate an uncontrolled descent. It is probable that the witnesses on the mountain got the impression that the light was falling because of their angle of view. The witness travelling from Bras-d'Or saw the aircraft just before and after the impact. The pieces of the aircraft were found very close to the coordinates he provided. As this witness saw the lights against a black background, he was unable to estimate the altitude of the aircraft. 2.3 Night Vision It is probable that the pilot flying the aircraft at the time of the accident could see the airport and the town of Lourdes-de-Blanc-Sablon in the distance. However, the human eye requires references like nuances of colour and shadow or details of relief to aid in judging distance and depth. In darkness, the eye cannot perceive these details; thus, our ability to judge heights is adversely affected. 2.4 Communications The fact that the witnesses saw the aircraft light indicates that the aircraft's electrical system was functioning and capable of powering at least one of the two radio transmitters. The normal tone of the co-pilot's voice and the absence of a distress call, at a time when the aircraft was at an unusually low altitude, indicate that the pilots were not aware that they were in a hazardous situation. 2.5 Vigilance It is plausible that the favourable weather, the pilots' familiarity with the airport, and the normal routine of the flight reduced the level of crew vigilance and did not prompt the pilots to validate their visual cues using the aircraft instruments. 2.6 Impact Characteristics Due to the uneven surface of the ice and the limited number of aircraft parts available, the angle of impact could not be determined. There was no evidence that the flight control surfaces failed in flight because of metal fatigue. It is highly improbable that the elevators and rudder failed at the same time. It is also improbable that the rudder tab would remain attached in flight if it was held only by its control rod. Moreover, the movements of the tab would have caused it to hammer against the adjacent surfaces, but that did not occur. Although it is plausible that the right wing folded back and caused the observed damage to the vertical stabilizer, fuselage, and horizontal stabilizer, the wing folded back during the impact. Catastrophic failure of the wings or the loss of the ability to command the flight control surfaces will cause the aircraft to descend in an abnormal position, usually in a dive. The absence of damage to the front of the nose cone and the deformation of the skin under the tail are more indicative of impact in controlled flight with a pull-up at the last moment. 3.0 Conclusions 3.1 Findings The crew were certified and qualified for the flight in accordance with existing regulations. The aircraft was certified, equipped, and maintained in accordance with existing regulations. There was no evidence found to suggest that there was an airframe failure or system malfunction prior to or during the flight. Witnesses observed the aircraft flying at an unusually low altitude. The altimeter setting was the same as for the previous flight. The altitude was not reported on the approach to the destination. No distress calls were transmitted. At night, it is possible to misjudge the height of an aircraft with reference to the ground or a frozen surface. 3.2 Causes The cause of the occurrence could not be determined; however, it is probable that the pilots did not monitor the altimeter properly and allowed the aircraft to descend until it struck the surface of the ice. 4.0 Safety Action 4.1 Action Taken 4.1.1 Accidents Involving Controlled Flight into Terrain The circumstances of this occurrence are typical of a Controlled Flight into Terrain (CFIT) accident. CFIT occurrences are those in which an aircraft, under the control of the crew, is flown into terrain (or water) with no prior awareness on the part of the crew of the impending disaster. The Board notes with concern that, over the 11-year period from 01 January 1984 to 31 December 1994, 70 commercially operated aircraft (not including those conducting low-level special operations) were involved in CFIT accidents. In view of the frequency and severity of such accidents, the Board is currently conducting a study of CFIT accidents to identify related systemic deficiencies. The International Civil Aviation Organization (ICAO) has recently released a task force report on CFIT prevention which recommends many changes to help reduce CFIT accidents. One of the recommendations is to eliminate 3-pointer altimeters, such as the altimeter involved in this accident.